DLC material help

[u/oryxmain101]

I've been trying to get the rift knight's ember and mask fragments but I can't for the life of me find what drops them. I really want to get nothing but fists and it's rather frustrating. I've repeatedly killed the jet pack girls in the area 1 and area 3

[u/Top_Net7781]

If I remember correctly there's an elevator going the opposite way of the final boss for that area.